Hadith 2428
´It was narrated from Abu Dharr:` That the Prophet commanded a man to fast on the thirteenth, fourteenth and fifteenth.
Hadith 2593
´It was narrated that 'Abdullah bin Mas'ud said:` "The Messenger of Allah said: 'Whoever asks when he has enough to make him independent of means will have lacerations on his face on the Day of Resurrection.' It was said: 'O Messenger of Allah, what would make him independent of means?' He said: 'Fifty Dirhams or its equivalent of gold."'
Hadith 4316
´It was narrated that Ibn Al- Hawtakiyyah said:` "Umar, May Allah be pleased with us on the day when we stopped at Al-Qaha?' Abu Dharr said: 'I was. A rabbit was brought to the Messenger Allah and the man who brought it said: I saw it bleeding (menstruating). The Prophet did not eat, then he said: "Eat." A man said: "I am fasting." He said: "What fast are you observing?" He said: "Three days each month" He said: "Why don't yo0u fast the bright shining days, the thirteenth, fourteenth and fifteenth."'